Any reading above 55 signals investors growing more optimistic. The index got there earlier this month. On July 5, it hit 58. Investors were feeling pretty good after celebrating America's independence and were hopeful that rate cuts in Europe and China would spur on some central bank stimulus.

But then worries about Europe's debt crisis overshadowed any mild enthusiasm. Still, nothing like a little good news from Corporate America to cheer investors up.

Second-quarter earnings have gotten into full-swing and it's shaping up to be a pretty decent reporting season. So far, of the 65 companies that have reported, 43 have beat estimates, according to S&P Capital IQ, which provides data for S&P 500 (SPX) companies.

The main catalyst behind the jump into greed? The number of companies hitting new 52-week highs. That indicator is now outpacing the number of firms hitting 52-week lows by a steady clip.

And demand for junk bonds, which offer high yields but also high risk, is up substantially.

But don't get too excited. There are still many hurdles that need to be overcome before the year is up. Europe, for one, is far from the finish line. And let's not forget the upcoming presidential election, coming this November.

Catherine Tymkiw is a news editor at CNNMoney where she helps oversee breaking news coverage and futures planning. Previously, she was the investing editor. Prior to joining CNNMoney, she was the online editor at Crain's New York Business and has nearly two decades of reporting and editing experience. She tweets @ctymkiwcnn